Crown prince Mohammed bin Salman's stewardship of the throne is being questioned.

Foreign investors were spooked by the recent crackdown on the Saudi elite.

Investors are worried that potential partners could fall victim to another corruption purge.

Mohammed bin Salman's consolidation of power is believed to have alienated many in the royal family.

As the heir to the Saudi throne, Mohammed bin Salman prepares to head off on a round of visits to western capitals to promote investment in the kingdom, his ambitious economic plans and even his grip on power are being increasingly questioned.

There are big doubts over foreign investors' willingness to back him in the wake of his recent shakedown of the Saudi elite; much debate about the amount of money he actually managed to raise; and suggestions that the episode, part of efforts to consolidate power, could backfire.

MbS, as the Crown Prince is known, has sought to draw a line under the recent detention of several hundred royals and prominent businessmen in Riyadh's Ritz-Carlton Hotel, where they were reportedly forced to sign over assets in return for their freedom.

Most of the detainees have now been released.

Gates of the Ritz-Carlton hotel are seen open in Riyadh. Thomson Reuters

The Saudi authorities have attempted to cast the seizure of assets as an anti-corruption drive, yet in a country where corruption is widespread the round-up appeared highly selective and showed scant regard for property rights and due process.

Commercially successful Saudi princes with international business empires and leaders of leading local companies were among the detainees, suggesting very strongly that no-one in the kingdom, apart from perhaps MbS's closest supporters, is immune to what looks like arbitrary justice.

Foreign investors will have observed the detentions and reported arm-twisting with alarm.

Foreign investors will have observed the detentions and reported arm-twisting with alarm. For most, corruption risk is a key consideration when exploring opportunities in the Saudi market. In the past, those looking to go into business with local companies would be advised to undertake robust due diligence to assess their counterparties' exposure to graft claims.

Now the concerns are much broader and deeper, essentially focused on the likelihood of a Saudi joint venture partner or private wealth client falling victim to another phase of this 'anti-corruption' purge. All the more so because the Saudis have yet to provide any evidence for the corruption allegations brought against the detainees.

That is despite the Attorney General Saud al Mojeb describing the crackdown as an "independent judicial process", part of efforts to ensure "transparency, openness and good governance". If that is the case, some are asking why there is such a deafening silence over what the former detainees are alleged to have done.

MbS took a huge gamble when he launched this campaign. He will have been aware of the risk of spooking foreign investors, but he seems to have calculated that with his oil-dependent economy in a distinctly unhealthy state it was critical that he raise funds to service the country's groaning budget deficit - this year expected to run to $52 billion - and to send a message to those not fully committed to his agenda.

At the outset, it was reported that he hoped to generate as much as $300 billion from the asset seizures, but as Alaco pointed out at the time this was hugely unrealistic because much of the detainees' wealth is tied up in complex financial structures overseas, beyond the reach of the Saudi state.

So it has come as no surprise that the total haul will be a mere fraction of the sum anticipated, with a highly credible story in the Financial Times, citing a senior Saudi official, reporting that the authorities are only counting on the acquisition of $13.3 billion in settlements by the end of the year, equivalent to the amount of revenue the country would receive from a small increase in the oil price.

The lean pickings are likely to be one of the main reasons why most of the detainees were released. Almost to a man, they were tight-lipped about their ordeal, only repeating the mantra that it was now "business as usual". They will have been ordered to say so because their companies and assets need to flourish for MbS to raise even the modest sums he is reportedly targeting.

Travel bans imposed on many of the former detainees aim to ensure that they stick to the task. But assuming the $13.3 billion estimate is accurate, how far will the sum go? It might ease some of the strain on the economy but MbS has already started to roll back on an austerity drive aimed at trimming the cradle-to-grave benefits enjoyed by ordinary Saudis - the only constituency he seems keen to keep onside - as part of wide-ranging economic reforms. Last month, the Crown Prince granted some $13 billion in handouts to state employees, the vast majority of the country's working population.

The extra public spending came amid public grumblings, expressed on social media, over the introduction of value added tax and gas-price hikes. It was the latest in a string of austerity measure U-turns which have cast doubt on his Vision 2030 plans to diversify the economy by developing the private sector and encouraging foreign investment. Further questions about the plans have been raised by the part-nationalisation of big conglomerates to which the government owes billions. The move was one of the outcomes of the Ritz-Carlton round-ups. But if MbS thought the forced takeovers might ease the deficit, recent demonstrations by unpaid workers from the soon-to- be-nationalised companies suggest otherwise.

Yet MbS has more serious worries on his plate. His rapid consolidation of power in recent months in preparation for his impending accession to the throne is believed to have alienated many in the royal family while both his attempts to ease some of the country's stifling social restrictions and the fruitless blockade of neighbouring Qatar appear to have riled prominent clerics, three of whom were arrested in September.

MbS holds most of the levers of power in the country, having sidelined, demoted and sacked many of his royal rivals. But his apparent reluctance to travel abroad to attend public engagements since the palace coup last June that saw him elevated to Crown Prince betrays a degree of nervousness. Indeed, there has been some hesitancy over the upcoming foreign trips. Visits to Britain and America have been subject to delays. That these trips have been planned at all suggests that MbS may feel more secure - and if they do go ahead it will confirm he believes that any internal challenge to his rule has receded.

All of which suggests the Crown Prince is not as unassailable as he seemed to be after displacing his cousin to become heir to the throne. With his economic plans seemingly unravelling, and dissent within royal and clerical ranks, he may have bitten off more than he can chew.

Ambrose Carey is a director at Alaco, a London-based business intelligence consultancy. He has particular experience in the Middle East and has been involved in some of the most high profile asset-tracing cases of the past few decades.